netfs: Fix a NULL vs IS_ERR() check in netfs_perform_write()

The netfs_grab_folio_for_write() function doesn't return NULL, it returns
error pointers.  Update the check accordingly.

Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/29fb1310-8e2d-47ba-b68d-40354eb7b896@moroto.mountain/

diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index e7f9ba6fb16bbe8e468f11a5694b001db78a6e34..a3059b3168fd95756c7e57986ed999e205dfa8aa 100644 (file)
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -221,10 +221,11 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
                if (unlikely(fault_in_iov_iter_readable(iter, part) == part))
                        break;
 
-               ret = -ENOMEM;
                folio = netfs_grab_folio_for_write(mapping, pos, part);
-               if (!folio)
+               if (IS_ERR(folio)) {
+                       ret = PTR_ERR(folio);
                        break;
+               }
 
                flen = folio_size(folio);
                offset = pos & (flen - 1);